by Barrie Anderson
I still recall the very first time I ever saw a Hydrangea. It was a paniculata type at a retail garden center some 25 years ago. I stopped in my tracks and ogled the massive, conical bloom heads. I had to have one of these, and purchased a Hydrangea paniculata ‘Grandiflora‘ (otherwise known by nurseries as the ‘Pee Gee’ Hydrangea) right then and there.
I was thrilled with my purchase of course, but had no concept of just how large this shrub would become. It grew rather quickly and after only two seasons in my garden it had more than doubled in size from 3 feet to just over 6 feet tall. Thankfully I planted this guy in the corner of my yard where it could grow as tall and wide as it desired. In the end, my beautiful Pee Gee would grow to almost eight feet tall and nearly seven and a half feet wide. The love affair had begun.
There are a plethora of Hydrangeas that will grow right here in Minnesota. The paniculatas, macrophyllas, arborescens, and anomala subsp. species are the best ones for our cold climate
Hydrangea arborescens sport the heavy, rounded ball look for their flowers. A few varieties of these that are very common in Minnesota gardens are Hydrangea arborescens ‘Annabelle’, ‘Incrediball’ and the ‘Invincibelle’ series. These hydrangeas bloom on new wood, so the absolute best time to prune these is in late winter or very early spring, before the snow has even melted. Please do this species a favor when pruning and cut it back to the ground. This is vital to promote stem vigor, which is critical for holding up those heavy blooms come summer. The best part of having these hydrangeas in your garden is they’re hardy to zone 3! These hydrangeas don’t overgrow their plot. They’re well-behaved and maintain a height and width range of three to five feet tall and four to 5 feet wide.
Next up is the macrophylla species. Sometimes referred to as the Big Leaf Hydrangeas or Mophead Hydrangeas, these guys are the fun ones that can change bloom color with some help. Be apprised though that this species will need extra attention from gardeners. The ‘Endless Summer’ variety is hardy here as a zone 4 hydrangea, and it blooms on both old and new wood, which typically means it is very cold hardy. To achieve those awesome blue blooms, you need to add some Aluminum Sulfate to the soil surrounding your ‘Endless Summer’. One should begin this process in late fall or very early spring to get a jump start on those beautiful blue blooms for summer! These guys are also well-behaved and stay within the three to four foot tall and wide range. Just remember this variety, because it blooms on both old and new wood, rarely needs pruning, but if you must prune, do it immediately after flowering so those buds for next year can get to work.
My favorite species of Hydrangea are the paniculatas! They have the most spectacular, conical, long-lasting blooms in my opinion. They are great for drying and decorating winter containers, and are stunning as cut flowers in floral arrangements as well.
These types of Hydrangeas will however, grow fairly large, and rather rapidly too, so be prepared to give them a location where they can reach their splendor! One of their unique qualities is they can really handle pruning. The paniculata species can be pruned at any time of year, with the exception of when they are forming their blossom heads. Did you realize that the paniculatas are the only Hydrangea that can be pruned into a tree form? Not to mention, they are hardy to zone 3, so Minnesota winters can come as they wish.
One of the most popular varieties of the paniculatas is ‘Limelight’. This is perhaps, my fave, second only to the Oak Leaf Hydrangea which we’ll encounter in another blog. ‘Limelight’ can reach a height of eight feet or more and just as wide too. It typically blooms from early summer to early autumn with flower heads as large as twelve inches in length! As the blooms age, they turn hues of cream, pink, red and burgundy. It truly is a sight to see, especially if you choose to plant these in a hedge. If you want a shorter version of ‘Limelight’ try ‘Little Lime’ or even ‘Bobo’. ‘Fire Light’ is a show stopper with its brilliant, reddish flower heads, and its size is comparable to that of ‘Little Lime’ and ‘Bobo’. Let’s not forget ‘Quick Fire’ as a sharp, showy, red paniculata. These are stunning in any landscape, but keep in mind these get as tall and wide as the ‘Limelight’, at around eight feet.
My mom and niece are pictured above standing in front of my mom’s ‘Limelight’ Hydrangea in one of her many garden areas. My mom’s about five foot two inches tall, and she prunes her ‘Limelight’ every year to keep it from getting so tall, but to keep it robust as well. This particular Hydrangea in my mom’s garden has a wonderful scent. Yes! The ‘Limelight’ Hydrangeas can be fragrant!
There are many more varieties of paniculata type Hydrangeas out there, but I’m going to let you enjoy researching some more flavors!
Bear with me for just one more Hydrangea species here in the upper midwest. Hydrangea anomala subsp. ‘Petiolaris’ is a vining Hydrangea! Yes! A true climbing Hydrangea that thrives here in Minnesota. As with most vines, these do grow fairly quickly after the first two seasons. In Minnesota I’ve seen these climbers reach a height of 15 feet and as wide as the Hydrangea wants. Their branching/twining habit is dense as well, and, using its aerial roots, will adhere to brick walls without issue. This plant can tolerate some shade too, and it’s very drought, heat, and humidity resistant. The flower heads are very noticeable, coming in at about seven to eight inches in diameter! This Hydrangea will definitely soften a wall or you can give it a trellis to work its magic and you will not be disappointed.
Hydrangeas. One of the more prolific blooming shrubs for Minnesota, that are extremely cold-hardy, durable, and did I forget to mention spectacular?
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